ABSTRACT The Epidemiology Research Core (ERC) supports population-based cancer research in metropolitan Detroit. The ERC is grouped in the Population Research Core Cluster along with the Behavioral and Field Research Core. The ERC is located within the Metropolitan Detroit Cancer Surveillance System (MDCSS), an NCI-funded population-based Surveillance, Epidemiology and End Results (SEER) Program central cancer registry. The MDCSS is located at Wayne State University (WSU), under the umbrella of the Karmanos Cancer Institute (KCI). Both Detroit and national SEER data contain detailed histological and demographic information, primary treatment and survival data for all patients with newly-diagnosed, invasive cancer in their respective geographic coverage areas. The ERC provides necessary support for access to and utilization of the very complex local and national SEER data for research. The Core also provides epidemiology consulting and collaborates with KCI members conducting investigations in cancer prevention, etiology, treatment and outcomes. This mission is achieved through services including rapid case ascertainment; collection of medical records and biospecimens; abstracting medical records for study-specific information; linkage of datasets to patient data for diagnostic, treatment, and outcomes research; identifying population-based control populations; research support and training for studies involving participant recruitment and interviewing; data queries and epidemiologic expertise and collaboration in the conduct of population-based investigations of cancer. The ERC benefits KCI by centralizing access to SEER data and standardizing patient, physician and hospital interactions for studies using SEER data for population-based research. The metropolitan Detroit population contains a large number of minorities, with 22% of the ~25,000 annual cancer diagnoses in the SEER catchment area being African American. This makes the population ideal for the study of health disparities. The ERC contributes significantly to the population-based research conducted at KCI, primarily through the identification of eligible participants and collection of data and biospecimens on these participants, evidenced in part by the 91 publications accomplished with support of the ERC during the current grant period.